This application is for partial support for participants in the Symposium "Monoamine Oxidase: Structure, Function and Altered Functions" to be held in Midland, Michigan, July 15-19, 1979. This symposium has been recognized as an official Satellite Symposium of the XI International Congress of Biochemistry (Toronto, Canada, July 8-14, 1979). Two previous symposia in this area have been held; Cagliari, Sardinia, 1971 and London, England, 1975. These two previous symposia have provided the only comprehensive publications on more recent developments on all aspects of this physiologically important enzyme, including clinically relevant material. The 1979 Symposium will follow by four years the most recent previous symposium. It is planned to have 25 invited speakers. Seventy additional participants can be accomodated. Seventeen of nineteen participants to whom invitations have been sent, have enthusiastically accepted. Sessions will deal with structure, inhibitors, active sites, altered functions, and advances in clinical medicine relevant to mental health, with ample time for discussions, and some contributed papers. The proceedings will be published within a year following the conference.